TGFβ1/integrin β3 positive feedback loop contributes to acquired EGFR TKI resistance in EGFR-mutant lung cancer

Integrins in Cancer Drug Resistance: Molecular Mechanisms and Clinical Implications

It is estimated that between 80 and 90% of mortality in cancer patients is directly or indirectly related to drug resistance. Consequently, overcoming drug resistance represents a significant challenge in the treatment of cancer. Integrins are transmembrane adhesion molecules that facilitate the linkage between the extracellular matrix (ECM) and the cytoskeleton, thereby enabling the activation of various cellular signaling pathways. Integrins are highly expressed in various cancers and contribute to cancer progression through invasion and metastasis. In addition, recent studies have revealed that integrins play a pivotal role in the development of drug resistance in cancer. This review will first provide an overview of integrin function and classification. It then discusses recent advances in understanding how integrins contribute to drug resistance in cancer, with a focus on ECM, drug transporters, the epithelial-to-mesenchymal transition (EMT), cancer stemness, PD-L1, and glycosylation. Finally, the potential applications of integrins as targets for therapeutic agents against drug-resistant cancers are also summarized.

Revealing a Novel Methylated Integrin Alpha-8 Related to Extracellular Matrix and Anoikis Resistance Using Proteomic Analysis in the Immune Microenvironment of Lung Adenocarcinoma

Genomic epigenetics of extracellular matrix (ECM) play an important role in lung adenocarcinoma (LUAD). Our study identified a signature of potential prognostic genes associated with ECM and constructed immune risk-related prognosis model in LUAD. We downloaded mRNAs transcriptome data, miRNAs expression data, and clinical patient information for LUAD based on The Cancer Genome Atlas. "Limma, clusterProfiler, ggplot2" R packages and GSEA were used to analyze meaningful genes and explore potential biological function. A competing endogenous RNA network was constructed to reveal the mechanism of ECM-related genes. Combined with clinical LUAD patients' characteristics, univariate and multivariate Cox regression analyses were used to build prognostic immune risk model. Next, we calculated AUC value of ROC curve, and explored survival probability of different risk groups. A total of 2966 mRNAs were differently expressed in LUAD samples and normal samples. Function enrichment analyses proved mRNAs were associated with many tumor pathways, such as cell adhesion, vascular smooth muscle contraction, and cell cycle. There were 18 mRNAs related to ECM receptor signaling pathway, and 7 mRNAs expressions were correlated with EGFR expression, but only 5mRNAs were associated with the long-term prognosis. Based on Integrin alpha-8 (ITGA8) molecule, we identified potential 3 miRNAs from several databases. The promoter of ITGA8 was higher-methylated and lower-expressed in LUAD. And lower-expressed group has poor prognosis for patients. 66 immunomodulators related to ITGA8 were performed to construct immune correlation prediction model (p < 0.05). Comprehensive analyses of ITGA8 revealed it combined focal adhesion kinase to activate PI3K/AKT signaling pathway to influence the occurrence and development of LUAD. A novel immune prognostic model about ITGA8 was constructed and verified in LUAD patients. Combined with non-coding genes and genomic epigenetics, identification of potential biomarkers provided new light on therapeutic strategy for clinical patients.

NRP1 overexpression potentially enhances osimertinib resistance in NSCLC via activation of the PI3K/AKT signaling pathway

Resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) is the main cause of mortality in lung cancer. This study aimed to investigate the roles of neuropilin 1 (NRP1) in non-small cell lung cancer (NSCLC). NRP1 expression was assessed in tumor tissues from patients with osimertinib-resistant (OR) NSCLC and osimertinib-responsive NSCLC as well as in patients with paracancerous NSCLC tissues who did not undergo radiotherapy or chemotherapy. In vitro experiments were conducted using five cell lines: BEAS-2B, HCC827, and PC9 cells, and the constructed OR cell lines, HCC827-OR and PC9-OR. HCC827-OR cells showing significant differences in osimertinib IC50 were selected for further study. After investigating the effects of altering NRP1 expression on cell sensitivity to osimertinib, NRP1 expression was inhibited to further investigate changes in cell viability, proliferation, migration, invasion, and apoptosis in OR cells. Additionally, bioinformatics techniques were used to detect targets (Integrin β3) and signaling pathways (PI3K/AKT) downstream of NRP1; subsequent cell experiments verified their interactivity. Finally, an orthotopic mouse tumor model was constructed using HCC827-OR cells treated with a PI3K/AKT signaling pathway activator (740Y-P), allowing exploration of the role played by the PI3K/AKT signaling pathway via NRP1 regulation on NSCLC resistance both in vivo and in vitro. Results showed that NRP1 expression was significantly increased in the cells of patients with NSCLC-OR, and increased NRP1 expression reduced HCC827 cell sensitivity to osimertinib. Both in vitro and in vivo experiments showed that NRP1 deficiency mediated by NRP1 inhibitors inhibited HCC827-OR cell proliferation, migration, and invasion, promoted tumor cell apoptosis, and enhanced osimertinib efficacy. In contrast, 740Y-P partially inhibited the effects of NRP1 inhibitors combined with osimertinib on the PI3K/AKT signaling pathway and on tumor growth in vivo and in vitro. Cellular experimental results showed that NRP1 positively regulates the Integrin β3 expression and activation of the PI3K/AKT signaling pathway. Bioinformatics analysis showed that both NRP1 and Integrin β3 may jointly participate in regulating the PI3K/AKT signaling pathway. In conclusion, our findings suggest that elevated NRP1 expression in NSCLC tumor tissues may promote NSCLC resistance to osimertinib by activating the PI3K/AKT signaling pathway, and integrin β3 potentially being involved in this process. These insights may provide a novel strategy for combination therapy for OR NSCLC.